UNUSUAL ARRANGEMENT OF STRATA. Ql)$ 



presents much irregularity in its minuter parts. But amid 

 so much confusion we observe Q pretty constant direction 

 from south-west by south to north-east by north, making 

 an angle of about 35° with the meridian. This situation of 

 the strata coincides with the aspect of the country, divided 

 into long hills, and narrow valleys, lying in the same di- 

 rection. But these valleys are not the only ones, that fur- 

 row the country ; for the hills are frequently intersected by 

 irregular valleys, commonly serving as a passage for the 

 rivers. 



Does not this agreement of the longitudinal valleys with Inferences. 

 the direction of the strata lead to the supposition, that their 

 origin is connected with the circumstances that formed the 

 strata, or gave them their inclination ? and the irregularity 

 of the tran verse valleys, and their agreement with the pre- 

 sent course of the waters, that they are owing to subsequent 

 events, produced by the course of some fluid? 



I shall conclude with an observation, the explanation of 

 which appears also to depend on hypotheses relative to the 

 causes of the inclination. 



All the strata of this country are composed in general of Alternation of 

 gritstone, schists, and biturneniferous carbonate of lime, fchi^and 

 £he reciprocal superposition of which announces a contern- limestone. 

 porary formation*. Yet we may observe in an intinite 

 number of instances, that the plains, or summits of the 

 hills, exhibit only gritstone or schist, while the declivities 

 present these strata alternating with limestone ; and that 

 the latter substance alone forms the bottom of most of the 

 longitudinal valleys f. I do not think this effect can be 



* All these are of secondary formation, and contain fragments of ; 



organized substances, such as vegetables, and animals without ver- 

 tebra;. 



t In these valleys are found many blackish pebbles, which I consi- Pebbles, 

 der as real quartz-agates (silex), possessing all the outer characters of 

 the kiesel'Schiefer. of the German mineralogists. This substance indeed, 

 like all the quartzes, is infusible, and Wiedenmann speaks of the fusi- 

 bility of the kiesel-schiefer. But may not this property be ascribed to 

 the accidental admixture of some calcareous particles ? an opinion the 

 more probable, as our black quartzes are frequently found in nodules iu 

 ^arbouate of lime. 



ascribed 



